Soft boot construction

ABSTRACT

IN A PRESSURIZED SUIT HAVING A CONVOLUTED ANKLE JOINT AND A FABRIC BOOT, THE ANGLE JOINT AND BOOT ARE CONSTRUCTED TO PROVIDE A CONFORTABLE AND EFFICIENT ANKLE JOINT. THE PATTERN FOR THE BOOT HAS A PARTICULAR GEOMETRY UTILIZING THE PRESSURE FORCES CREATED WITHIN THE BOOT FABRIC IN SUCH A WAY AS TO PROVIDE A VERTICAL WALL OF SUFICIENT RIGIDITY, AT LEAST IN THE INSTEP AND HEEL AREAS, TO AVOID ANY PRESSURE POINTS AT THESE LOCATIONS.

p 1 E. GETCHELL ETAL 3,605,293

SOFT BOOT CONSTRUCTION Filed Dec. 20, 1968 2 Sheets-Sheet 1 F/G. PRIOR ART 12 M 2/ I Z4 OUGLQZ ETZEiHELL OH N J. KORABOWSKI a 5 PRIOR RT .7 1 MICHAEL A. MARRONI JR (liar/m AGE NT Sept. 20, 1971 GETCHELL ETAL 3,605,293

SOFT BOOT CONSTRUCTION Filed Dec. 20, 1968 2 Sheets-Sheet 8 FIG. 7

United States Patent O 3,605,293 SOFT BOOT CONSTRUCTION Douglas E. Getchell, Windsor Locks, Conn, John J.

Korahowski, Springfield, Mass, and Michael A. Marroni, Jr., Weatogue, Conn, assignors to United Aircraft Corporation, East Hartford, Conn.

Filed Dec. 20, 1968, Ser. No. 785,616 Int. Cl. A431) 1/02 US. Cl. 36-9 Claims ABSTRACT OF THE DISCLOSURE In a pressurized suit having a convoluted ankle joint and a fabric boot, the angle joint and boot are constructed to provide a comfortable and efiicient ankle joint. The pattern for the boot has a particular geometry utilizing the pressure forces created within the boot fabric in such a way as to provide a vertical wall of sufficient rigidity, at least in the instep and heel areas, to avoid any pressure points at these locations.

BACKGROUND OF THE INVENTION The present invention relates to a pressure suit and more particularly to a boot construction therefor, which provides joint mobility, particularly at the ankle joint.

Obviously, many conventional boot or shoe patterns may be utilized in fabricating or manufacturing boots of the fabric or soft type for pressure suits. However, it has been determined that when these conventional boot or shoe patterns are utilized to fabricate a soft boot that is to be employed with a unidirectional convoluted ankle joint attached to the top of the soft boot and when the suit is pressurized, a collapsing of the boot instep occurs resulting in an unacceptable pressure point at this point on the wearer. Simultaneously, a cutting in at the top of the heel section also occurs, resulting in another unacceptable pressure point, the result being discomfort to the wearer and a reduction in ankle mobility.

When a unidirectional convolute system is placed on a pressure boot, the problem of cutting in at the instep and heel sections of the boot may be resolved in a number of ways. One such construction which would tend to eliminate this cutting-in problem is to increase the circumference of the convolute section so as to lower the attachment point of the convolute to the boot at a point well below the instep region of the wearer. However, this results in a much larger circumference for the convolute system thereby increasing the torque and increasing the overall bulk and size of this system. Obviously, the disadvantages of this system are clear.

A second way of reducing the instep cutting-in problem is to raise the convolute system to a relatively higher point above the instep than is normally desired, thus providing a certain amount of height in the boot patterns and supplying a region of rigidity at the top of the boot to resist the collapsing forces produced by the effects of the convolute system. However, this results in the location of the ankle convolute system in a much higher position than the wearers ankle joint and would result in ineffieciency of performance of the ankle joint.

A third approach would be to contour reinforcement sections of a rigid material such as fiberglass, aluminum, steel or plastic and thus mechanically provide the necessary shape of the boot to prevent the boot from collapsing or cutting in under the effects of the convolute. However, this would result in an increased weight, increased complexity of fabrication and unpressurized discomfort to the subject.

Obviously, one additional solution to this cutting-in problem would be to eliminate the convolute system com- 3,605,293 Patented Sept. 20, 1971 pletely; however, if this is done, a more conformal boot would result, reducing ankle mobility or possibly even eliminating completely the ankle mobility.

SUMMARY OF THE INVENTION It is a primary object of the present invention to provide a boot construction for use with a unidirectional convolute pressure suit, which provides efiicient and adequate ankle mobility.

The problem of cutting in at the instep and heel areas of a fabric or soft-type boot is peculiarly unique to a pressure suit which utilizes a convolute system in the ankle area. This cutting-in problem results from the pressurization or more specifically the supplying of an internal pressure to the convolute system thereby causing a vertical load or force to act on the convolute and hence force the convolute to expand downward and cause the boot to neck-in in the instep and heel area. The present inventin overcomes the tendency of the boot instep and heel to neck down or drop down under the vertical load of a convolute by providing a shape for the boot that has an area of rigidity immediately below the convolute attachment point. More specifically, this rigidity is achieved by incorporating a vertical wall section at the instep and heel of the boot which will not collapse or drop down under the convolute vertical load.

Since the foregoing problem only occurs when the suit is pressurized, the following description will be directed at this condition. The aforementioned vertical wall area is achieved by applying a force at each side of the boot at the top, causing the opening at the top of the boot to flutter from a normally substantially cylindrical shape to an elliptical shape with the major axis extending from the front or instep area to the back or heel area. This flattening effect or change in shape from a cylindrical to an elliptical shape is accomplished by utilizing a unique pattern, which is employed in fabricating the soft boot. The unique pattern of the present invention employs at least two panels, a first panel encasing the toe and front foot portion, the second panel cooperating around the heel and ankle area. It has been determined that by judiciously arranging the dimensions between particular points on the second panel, or more particularly controlling the geometry of the second panel, the pressure forces created in the fabric material of the second panel may be vectored and oriented to bias or compress the midpoint between the instep and heel area and cause the boot to assume an ellip tical shape. In other words, when the boot is pressurized, the geometry of the second panel is such that it vectors the pressure forces and induces a radially inward force component on each side of the boot, substantially midway between the instep and the heel, the line of force corresponding to the minor axis of the elliptical shape of the boot.

It is also desirable to have a boot construction which provides a curved contoured bottom in which both the inseam and outseam are substantially co-planar when the boot is pressurized. The first panel of the boot pattern of the present invention is unique in that it accomplishes this. It does so by providing a pattern where the inseam and outseam are not co-planar in the unpressurized conditions; however, when pressurized, the forces are vectored and oriented such that the seams are caused to take co-planar positions.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a conventional pattern for fabricating a typical prior art boot.

FIG. 2 is a side view of a pattern for fabricating a boot construction in accordance with the teaching of the present invention.

FIG. 3 is a fragmentary illustration of a conventional boot construction for use in a convolute suit showing the undesirable features thereof in the pressurized condition.

FIG. 4 is a fragmentary illustration of the boot construction of the present invention in conjunction with a convoluted suit in the pressurized condition.

FIG. 5 is a view substantially along line 5-5 of FIG. 1.

FIG. 6 is a view substantially along line 66 of FIG. 2.

'FIG. 7 is a pattern drawing for fabricating a boot in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Since the present invention is primarily concerned with providing mobility in the ankle area of a suit of the pressurized type, for the sake of brevity and clarity, the description of the present invention will be specifically limited to the ankle environs.

FIGS. 1 and 3 illustrate a conventional pattern for a boot and the undesirable features which result from the use of the conventional boot with a convoluted ankle joint. As can be clearly seen in FIG. 3, the conventional construction comprises a boot 2, shown pressurized, which encases the wearers foot and a portion of his ankle, the boot and generally the rest of the suit being fabricated from any suitable material, a fabric generally being a preferred type of material. Boot 2 includes an instep area, indicated generally by reference character 4 and a heel area, indicated generally by reference character 6. Obviously, boot 2 includes an opening 9 in its top to permit the insertion of the wearers foot, opening 9 which is normally cylindrical primarily because the convolutes, hereinafter described, cause the opening to be cylindrical. Opening '9 is clearly illustrated in FIG. 5. Attached to the top of boot 2 is suit ankle joint 8 which includes a plurality of convolutes 10. Restraining the expansion of the convolutes 10 in one direction, thereby making the convolute system a unidirectional one, is a pair of restraint straps, restraint strap 12 being shown and a similar one diametrically opposite thereto not being shown. It is clearly illustrated in FIG. 3 that restraint strap 12 is connected to the suit structure at one end and to the boot 2 at the other end.

When the suit and hence ankle joint 8 and boot 2 are pressurized by supplying an internal pressure thereto, the undesirable features of the conventional construction become apparent. As a result of this pressurization, a pressure force F is created in the convolutes 10, this pressure force thereby resulting in a compressive type force which acts on the top of boot 2. As a result of this compressive force, the instep area 4 tends to neck in or cut in as indicated by reference character 12, hence causing discomfort to and reducing mobility that the wearer might have in the instep area. Similarly, the compressive force results in a cutting in or necking down of boot 2 in heel area 6, as indicated at 14. It can therefore be seen that the use of a conventional pattern to fabricate a boot of a fabric material for use with a suit having a convoluted ankle joint results in substantial reduction of mobility and comfort of the ankle joint 8.

Reference is now made to FIGS. 2 and 4 illustrating the pattern for manufacturing a boot in accordance with the present invention and the desirable results obtained therefrom in a suit utilizing a convolute ankle joint. The basic concept of the present invention is to overcome the cutting in of boot in the instep and heel areas 22 and 24 respectively, as a result of the convolute loads, by providing a shape for boot 20- that has an area of rigidity immediately below the convolute attachment edge 26. This area is illustrated in FIG. 2 and is represented in the instep area 22 by the line A-A and in the heel area 24 by the line B-B'. It is to be borne in mind, however, that this area of rigidity extends around the entire periphery of the boot at its attachment edge to the suit 4 ankle joint and not only in these two critical areas. However, since the primary cause of reduced ankle mobility and discomfort results from the pressure points occurring in the instep and heel area as a result of the convolute pressure load, it is believed to be necessary to provide a substantially vertical wall section in the instep and heel area, as indicated by A-A and B-B respectively.

Normally boot 20, which is constructed of a similar fabric as boot 2 of FIG. 1, contains a cylindrical opening for insertion of the wearers foot into boot 20, the opening being formed primarily as a function of the shape of the suit at the edge of attachment 26. It has been found that if this normally cylindrical opening is caused to assume or flutter to an elliptical shape in the pressurized condition, a substantially vertical wall of rigid section at A-A' and B-B is provided. This desired shape of the boot is illustrated in FIG. 6, it being clearly shown there that the major axis 32 extends from the instep area 22 to the heel area 24 and therefore the minor axis 34 extends from one side of the boot 36 to the other side of the boot 38.

To accomplish this flattening effect of the boot opening 30, or more specifically to induce the normally cylindrical opening to assume an elliptical shape when the boot is pressurized and thereby provide a cylinder or tubular section of material with sufficient height and rigidity to withstand the pressure force from the convolute, the present invention utilizes a unique pattern. In describing this unique boot pattern, reference will be made to the conventional boot pattern shown in FIG. 1, thereby providing a ready basis for the causes of the undesirable conditions and how the unique pattern of the present invention overcomes these undesirable characteristics.

Referring first to FIG. 1, it is seen that one side of the conventional pattern is comprised of a single side panel 40. This panel includes a shaped contour portion 42 which comprises the instep area 4 of boot 2. The shaped contour of instep area 4 is determined by two primary dimensions, the lateral dimensionv 0 from a point substantially midpoint between the instep and heel to the base of the contour, and the transverse dimension P from a point at the forward heel area 44 to the apex 46 of shaped contour 42, apex 46 also being the junction of contour 42 and edge 26. Similarly, in heel area 6 there are two significant dimensions, these being the transverse dimension R from a point 60 midway between the instep and heel and the base of the heel '47, and the transverse dimension S between the forward portion of the heel 44 and the top or apex of the heel 48. Each of these dimensions has significance because it is believed that the arrangement of these dimensions determines the direction of the forces created within the fabric when pressurized and the shape and amount of material available at the boots edge of attachment to the convoluted ankle joint.

The boot of the present invention is illustrated in FIG. 2. As seen, the pattern comprises a first panel 50 and a second panel 52, the first panel being the forward section of the boot and the second panel encasing the heel and ankle portion of the wearers foot. For the sake of clarity, first panel 50 and second panel 52 are illustrated as being connected only at heel 44; however, it should be obvious that the first and second panels 50 and 52 are attached to one another along edge 51 and at 44' by any conventional means such as stitching. This particular connection is clearly shown on FIG. 4 as at 51. It is in the second panel 52 that the most significant modifications have been made to provide the vertical wall of rigidity below the edge of attachment 26 to ankle joint 8. By altering and modifying the lateral and transverse dimensions hereinbefore described in conjunction with the prior art construction of FIG. 1, it has been determined that the forces created in the fabric material of the second panel 52 can be vectored or oriented such that a radially inward force component is created at a point substantially midway between the instep and the heel at each side of boot 20 thus causing the opening in boot 20 to flatten or assume an elliptical shape. [It has additionally been determined that a wall of c'ylindrical material of suficient height and rigidity to resist the convolute pressure force is provided. More specifically, this is accomplished by lengthening the transverse dimension between the forward heel portion 44 and the apex 46' of the shaped contour 42, indicated as P and the transverse dimension between the forward heel position 44' and the apex of the heel portion 48 indicated by reference character 8' on FIG. 2, and by shortening the lateral dimension between midpoint 60' and the base of the shaped contour 43 indicated by O, and the transverse dimension between the midpoint 60 and the base of the heel 47 indicated by reference character R. The effect of shortening the lateral dimension of O to O and the transverse dimension from R to R is to cause midpoint 60' to be pulled or moved toward the base of the shaped contour 42' and the base 47 of the heel. This results in moving the apex 46 of shaped contour 42' inward, hence reducing the width of the boot opening at its top and aiding in inducing a radial force component to be exerted along the minor axis of the boot opening. The effect of lengthening the transverse dimension from P to P and the transverse dimension from S to S is to cause more of the fabric material to move into the shaped contour area 42' and heel area 24 thereby tending to increase the dimension from the instep to the heel.

More specifically, it is believed that by lengthening and shortening the dimensions as described herein that the tensile forces and the normally outwardly directed pressure forces created in the fabric of boot 20 by the application of internal pressure can be vectored or oriented to produce a radially inwardly directed force component substantially midway between the instep and the heel at each side of the boot. Additionally, the change in geometry provides the desired vertical wall of material at the edge of attachment. It is pointed out that only one side of the second panel has been discussed, but it should be clear that the dimensions on both sides of the panel are altered.

The first panel 50 partially comprising the boot of the present invention is unique in that it provides a desirable curved bottom 51 when the boot is pressurized. To accomplish this, first panel 50 and second panel 52. bias the pressure forces created in the fabric of the first panel 50 and vector them so that a desired shape is obtained. Referring again to FIG. 2, it is seen that first panel 50 contains at least one inseam 54 and. an outseam 56. The significant dimensions in first panel 50 are transverse dimensions X and X.

Dimension X is the dimension between inseam 54 and the apex 58 of first panel 50 while X is the dimension between outseam 56 and apex 58. By providing a pattern wherein dimension X is shorter than dimension X in the unpressurized condition, a boot with a desired curved bottom is obtained in the pressurized condition. This is accomplished because it was found that in a pressurized boot utilizing a conventional boot pattern, the pressure forces therein caused a twisting of the boot bottom. By biasing the fabric material in the pressurized condition, i.e., providing more fabric on the inseam 54 as opposed to the outseam 56, a construction is provided which COlIlJ- pensases for and accommodates this twisting phenomenon and provides a boot with the desired curved bottom. More specifically, since the pressure forces would normally cause the outseam fabric to move more than the inseam fabric, by providing this excess material and permitting the pressure forces to act thereon, a co-planar inseam and outseam are provided in the pressurized condition.

One additional feature which the present invention employs in providing a boot and a convoluted ankle configuration with acceptable mobility, is the use of a heel counter 68 (see FIG. 4). Heel counter 68' is a wedgeshaped member extending from the forward heel area 44' to partially up the vertical portion of the rear heel area '24. The function or purpose of heel counter 68 is to further aid in providing the desired rigidity.

A pattern for incorporating all of the foregoing features is illustrated in FIG. 7. As shown therein, three separate panels are utilized, a first panel 90, comprising sections a and 90b, which are connected together preferably by stitching and which encases the front part of the wearers foot, a second panel 92 comprising sections 92a and 92b, the two sections being connected together and encasing the wearers instep and a portion of his heel, and a third panel 94 comprising sections 94a and 94b, the sections being connected together and conforming to the wearers heel and encasing this portion. Third panel 94 is primarily directed to providing comfort to the wearer by conforming the soft boot more closely to the wearers foot and includes cutout portion 98 within which boot counter 68 cooperates.

Also illustrated on FIG. 7 is a tongue portion 96 and a sole portion 97, each section of the boot construction, that is, the first, second and third panels, the tongue and sole section being connected together by any conventional method along the appropriate seams. It has been found that sewing or stitching the members together along the seams of each member is an acceptable method.

We claim:

1. In a boot of a fabric type for use with a pressurized suit having a convoluted ankle construction, the method of providing ankle mobility comprising:

providing a substantially cylindrical boot opening for the insertion of a foot therethrough in the unpressurized condition;

vectoring the forces created in the boot and biasing these forces so as to cause the substantially cylindrical opening to assume a substantially elliptical shape when the boot is pressurized; and

providing a substantially rigid vertical fabric wall, the

fabric wall extending downward from the top of the boot and having sufiicient height to resist any pressure forces applied thereto.

2. The method of providing ankle mobility as in claim 1 wherein;

the elliptical-shaped opening is provided by inducing a radially inward force component to act upon each side of the boot opening, this line of force being substantially the minor axis of the elliptical-shaped opening.

3. The method of providing ankle mobility as in claim 2 including:

causing the major axis of the elliptical-shaped opening to lie in a plane substantially parallel to the plane of the convolutes by vectoring the radially induced fjorces so that they are applied at each side of the oot.

4. A boot construction for use with a suit having a convoluted ankle construction, the boot and ankle construction cooperating to encase a wearers foot comprismg:

at least a first panel of a fabric material, the first panel being shaped to extend substantially from the base of the instep area of the ankle to and around the toe area of the foot;

at least a second panel of a fabric material, the first and second panels being connected to one another, the second panel being so shaped so as to encase the instep and heel areas of the foot and ankle, the geometry of the second panel being such that the forces existing therein when the boot is pressurized are vectored so that a radially force component is generated in the second panel tending to compress the topmost portion thereof, the radial force component causing the topmost portion of the second panel to change from a substantially cylindrical shape to a substantially elliptical shape.

l 5. A boot construction as in claim 4 wherein; contoured portion being controlled as a function of the major axis of the elliptical shape extends from the transverse dimension between the apex of the the instep area to the heel area. contour and a predetermined point on the heel sec- 6. A boot construction as in claim 4 wherein; tion of the second panel and by the lateral dimension the geometry of the first panel is so shaped that when 5 between a point substantially midway between the in the unpressurized state the outseam of the first instep and the heel and the base of the profile of the panel is in a relatively higher position than the incontoured portion. seam of the first panel, and when pressurized, the in- 9. A pattern construction for manufacturing a boot as seam and outseam assume substantially co-planar in claim 8 wherein; positions. 10 a substantially rigid vertical wall at the topmost sec- 7. A boot construction as in claim 5 wherein; tion opposite the instep is provided in the pressurized a boot counter of substantially rigid material is 10- a e, he profile of the topmost section in the heel cated in the lower portion of the heel, the boot area being controlled as a function of the transverse counter being substantially wedge-shaped and exdimension between the said predetermined point on tending from the front portion of the heel to the the heel and theapex of the topmost section in the rear portion of the heel, heel area and the said transverse dimension between 8. A pattern for manufacturing a boot assembly which midp in ee the ins ep and heel and t e fully encases a wearers foot, the boot being adapted for p of the l wer h l e tion. use in a pressurized suit having a convoluted ankle con- A Pattern Construction for manufacturing a hoot struction comprising: as in claim 9 wherein;

at least a first panel of a fabric material, the first panel the first and second Panels are Connected together at being shaped to extend substantially from the base least at the Said predetermined Point in the heel of the instep area of the foot to and around the toe area, this P0h1t being located at the forward POrtion area of the foot, of the heel. at least a second panel of a fabric material, the first and second panel being connected to one another, References C'ted the second panel leaving an opening in its topmost U T S TES A ENTS section for insertion of the foot thereinto, the second 2,989,752 6/1961 Slo n et a1, 2-2.1 panel including a contoured portion sloping down- 3,128,567 4/ 196 4 Huard 36--48 ward from the topmost section and corresponding 3,411,156 11/1968 Feher 2--2.1

substantially to the contour of the foot instep, the profile of the contour and fabric available to the PATRICK D. LAWSON, Primary Examiner 

